Our continued study of molecular mechanisms and metabolic patterns in brain monoamine systems in relation to drugs and to clinical manifestations of their effects will have three primary areas of emphasis: 1) Further demonstration of the effects of particular drugs of abuse and psychotherapeutic drugs (as well as combinations of the two) on such aspects of biogenic amine function as intra- and extracellular concentrations of amines in regions of rat brain; the dynamics of the pterin cofactor subserving tyrosine and tryptophan hydroxylation; the repercussions of electrophysiological kindling phenomena; and the kinetic morphology and regulation of tryptophan hydroxylase and tyrosine hydroxylase. 2) Elucidation of the functional relevance of hemispheric asymmetries in biogenic amine mechanisms and their native rhythms as well as their fluctuations in response to drugs (including asymmetries of amine levels per se, of enzyme morphology and activity, of synaptosomal amine synthesis, of electrophysiological discharge) and the absence of similar hemispheric fluctuations in the distribution of the pterin cofactor involved in amine synthesis. 3) Exploration of the possibility that quantization in enzyme kinetics and electrophysiological coherence as both relate to fluctuation phenomena and hemispheric asymmetry may point to the which neurobiological phenomena are transduced into subjective experience and behavior.